function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
      var c = ca[i];
      while (c.charAt(0)==' ') c = c.substring(1,c.length);
      if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
 
   return null;
}
 
function createCookie(name,value,days) {
  if (days) {
      var date = new Date();
      date.setTime(date.getTime()+(days*24*60*60*1000));
      var expires = "; expires="+date.toGMTString();
      document.cookie = name+"="+value+expires+"; path=/";
  }
  else
  {
      var expires = "";
      document.cookie = name+"="+value+expires+"; path=/";
  }
}
 
//get query string
function gup( name ){
  name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
  var regexS = "[\\?&]"+name+"=([^&#]*)";
  var regex = new RegExp( regexS );
  var results = regex.exec( window.location.href );
  if( results == null )
    return "";
  else
    return results[1];
}
 
var id_param = gup('id');
 
//only perform cookie checking when there is no id
if (id_param != ""){
    var existcook = readCookie('ads_id');
    if (existcook) {
      //do nothing	
    }
    else{
      createCookie('ads_id', id_param, 6);
    }
}